1. Field of Invention
The present invention pertains to a resource allocation apparatus, a central control apparatus, a wireless base station, a wireless communication system, a resource allocation method and a resource allocation program in a computer-readable medium, for allocating resource information needed to perform wireless communication for a wireless base station including an access-side wireless interface for covering wireless terminal devices and a backbone-side wireless interface for connecting wireless base stations with each other.
2. Description of Related Art
Recently, in a case where wireless base stations are installed, a wireless mesh network is desired to be connected not with cables, but wirelessly for easiness of installation, tolerance for failures or the like.
In this case, to improve capacity between the wireless base stations, it is considered to mount a plurality of wireless network interfaces in the wireless base stations.
When a 2.4 GHz wireless LAN is applied, as non-interfering (non-overlapping) wireless channels in frequency allocation in the 2.4 GHz wireless LAN, there is a maximum of only three channels (for example, 1ch, 6ch, and 11ch) within the United States.
However, since maximum ranges of the wireless channels are different depending on wireless methods and countries, the number of non-interfering (non-overlapping) wireless channels is also different depending on the wireless methods and countries.
Therefore, the wireless base stations including a number of wireless network interfaces have a problem of channel interference.
When channel interference occurs, network performance worsens.
For this reason, to prevent channel interference, Japanese Patent No. 3600568 (document 1) discloses a wireless communication apparatus enabling an empty channel that is not used for communication to be automatically set as a communication channel.
However, a technique of document 1 can be applied only to an access-side wireless interface for covering wireless terminal devices.
Therefore, in a case where the technique of document 1 is applied to a backbone-side wireless interface for connecting wireless base stations with each other, non-overlapping wireless channels are allocated, so that the wireless channels cannot be shared, and consequently, communication between the wireless base stations cannot be performed.
For this reason, the technique of document 1 cannot be applied to a wireless base station configured to include an access-side wireless interface and a backbone-side wireless interface.
US 2005/0208949 (document 2) discloses a channel allocation method of performing channel allocation according to traffic for a backbone-side wireless interface.
However, a technique of document 2 is used to perform channel allocation according to traffic for the backbone-side wireless interface only and does not consider channel allocation associated with the access-side wireless interface.
Therefore, in the technique of document 2, interference between the backbone-side wireless interface and the access-side wireless interface occurs.
For this reason, the technique of document 2 cannot be applied to the wireless base station configured to include the access-side wireless interface and the backbone-side wireless interface, similarly to the case of document 1.
In addition, the prior-art Japanese Patent Application Laid-Open No. 2002-345016 (document 3) discloses a wireless channel allocation method that enables wireless channels to be allocated to each wireless link without variance in a mesh type wireless network.
However, a technique of document 3 is that even when each upper node autonomously and distributively sets the wireless channels allocated to a link of the upper node, different wireless channels are prevented from being allocated to the same link by a plurality of upper nodes.
Therefore, the technique of document 3 does not consider allocating wireless channels to the access-side wireless interface and the backbone-side wireless interface so that interference between the access-side wireless interface and the backbone-side wireless interface does not occur in the wireless base station including the access-side wireless interface and the backbone-side wireless interface.
In addition, there is a document that discloses a scan scheme of an active scan scheme or a passive scan scheme, or a technique of a spectrum or spectrum mask (see, for example, ISO/IEC 8802-11 IEEE Std 802.11 Second edition 2005-08-01 ISO/IEC 8802 11:2005(E) IEEE Std 802.11i-2003 Edition, Information technology—Telecommunications and information exchange between systems—Local and metropolitan area networks—Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications (Includes IEEE Std 802.11, 1999 Edition; IEEE Std 802.11a.-1999; IEEE Std 802.11b.-1999; IEEE Std 802.11b.-1999/Cor 1-2001; and IEEE Std 802.11d.-2001 (hereinafter referred to as Non-Patent Document 1)).